Tube Question - Do they need time to "Break In"


Other than a Preamp/Amp's given warm up time...do tubes need time to mature or settle in similar to a new speaker?
chadlesko
Just overnight or aprox 24 hrs.
No. They simply need to warm up to ideal operating temperature.

Tubes actually do not break-in,it is the opposite, they start ''breaking-down'', losing their efficiency hour-by-hour until they no longer provide musical satisfaction and have to be replaced.

Just keep it simple and enjoy them.....
>>02-07-09: Thorman
Just overnight or aprox 24 hrs.<<

Wrong.

Only the time taken to reach operating temperature; the dielectric is a vacuum.
Yikes, Audiofeil, play nice...

Follow-up question. How long do tubes take to reach operating temperature?

I ask because I'd imagine that wouldn't take more than a few minutes (not sure, which is why I asked), but my tube amp and pre sound better after an hour or so.

I know that's not break-in, but something is going on inside those vacuums!
Thanks everyone for the response...I'm changing tubes for the first time...
I'm just answering your question.

There are other parts, capacitors for instance, that sound "better" with some time.

Don't forget the "human factor" as well. You become acclimated and more comfortable (in most cases) after a bit of listening. You may perceive the system as sounding "better" as a result.

Lastly, much of our enjoyment or dissatisfaction with our system is dependent on emotional state. I'd bet that after a good meal, your favorite team winning, or a relaxing day the system sounds great.

Conversely, after a fight with the wife, bad day at the office, or having the air conditioning crap out on a hot/humid day your system may not sound as "great" as the day before when everything was running smooth.

IMO of course.
My preamp takes about an hour before it sounds best too. I think the warmup period is not for the tubes, but for the other electrical components within the preamp.
My experience is that tubes do take time to break in. Two years ago, I bought a pair of new Full Music Meshed-plate 300Bs for my SET amp. When I first powered them on, they would not even hold biases. They also sounded muddy and closed. If you looked at the meshed plates long enough, you could see their brightness changed!

After 200-300 hours, they started to open up and hold the bias levels. Now they work perfectly. I really like these tubes!
Do you wait until they're warmed up before playing music? My McIntosh has about a 30-second "tube-warmup" before it'll play. It literally display "tube-warmup" on the front LEDs. My Cary 120S manual says warm-up time is 3 minutes. The tech at Cary Audio said it was ok to start playing pumping music through as soon as the amp is turned on but I take his technical advice with a grain or two of salt.
02-07-09: Cyclonicman
My preamp takes about an hour before it sounds best too. I think the warmup period is not for the tubes, but for the other electrical components within the preamp.
Bingo.

I have some all-tube guitar amps, and once the tubes are up to operating temperature, they're ready. Having been a solid state hi-fi guy for decades, I was really surprised that I could immediately hear the difference when I swapped in some '60s-era NOS RCA grey glass 6V6GTs for the stock Sovteks in my all-tube (including rectifier) Top Hat combo amp. No break-in or settling in required. I think it's the SS components that take awhile to reach optimum operating temp and attendant tolerances. I keep many of my SS components on all the time for this reason.
In my experience, my tube integrated sounds its best after about an hour and a half. It will sound great almost immediately, but even better after about 90 minutes. I also would say that the sound of the amp definitely improved over the first 200 hours or so. Do they have to do these things to sound good? No. But they do improve over that time, yes.
>>Thanks everyone for the response...I'm changing tubes for the first time...
02-07-09: Chadlesko<<
>>>>>>>>>>>>>>>>>>>>>>

Chadlesko,
New tubes do require burn-in time to reach their full sonic potential.

Here is an example. Read on page (3) what Cary has to say about burn-in time for tubes in a preamp of theirs.

Check out page (54), A Taste of Tubes

Quote from page 54:
"Their performance initially improves during the first few hundred hours, followed by an extended performance plateau region. Finally, after several thousand hours of use they slowly f-f-f-fade away."

Will you need to wait a hundred hours for your new tubes to sound really good? Probably not.... But they will take a hell of a lot longer than just an hour or so.
.
Johnny I have an Audio Research tubed preamp and it has a 45 second power up before you can actually play it, however, the owners manual actually states that the preamp will sound better if warmed up for an hour, which it does!